(CNN) — A Tulsa dentist who health investigators say may have exposed thousands of patients to HIV and hepatitis because of unsanitary practices also allowed “unauthorized, unlicensed” employees to perform intravenous sedation of patients, Susan Rogers, executive director of the Oklahoma Board of Dentistry, told CNN’s “Starting Point” Friday.

“That is completely unacceptable and illegal in Oklahoma,” Rogers said.

Investigators do not know if that practice led to infections in any patients of W. Scott Harrington, who voluntarily stopped practicing after a joint investigation by city and state health departments uncovered numerous violations.

The state health department is contacting some 7,000 patients seen by Harrington since 2007 to urge them to be tested for Hepatitis B, Hepatitis C and HIV.